1. Field of the Invention
The present invention relates generally to electronic apparatus, and in a preferred embodiment thereof more particularly relates to keyboard structures for portable computers, such as notebook computers, and associated cursor positioning pointing stick devices.
2. Description of Related Art
In recent years the notebook computer has made considerable gains in both popularity and technical sophistication. One factor contributing to the increasing popularity of the notebook computer is its ever decreasing size and weight, a factor arising from the ability to fabricate various components of the computer in smaller and smaller sizes while, in many cases, increasing the power and/or operating speed of such components.
One continuing challenge in the design of notebook computers, however, is the keyboard structure. This design challenge arises from two conflicting design goals--the desire to even further reduce the size of the keyboard structure, and the desirability of having the notebook computer emulate as closely as possible the size and typing "feel" of a desktop computer keyboard.
There are, of course, two dimensional factors which may be varied to reduce the size of a notebook computer keyboard structure--its horizontal dimensions (i.e., its length and width), and its vertical or thickness dimension. The horizontal dimensions of the keyboard are governed by the number, size, and relative spacing of the manually depressible key cap portions of the keyboard, and various reductions in these three dimensional factors may be utilized to reduce the overall length and/or width of the keyboard. However, as will be readily appreciated, a reduction in these three configurational aspects to gain a keyboard size reduction correspondingly lessens the similarity of the notebook computer keyboard in appearance, key arrangement and typing feel to its desktop counterpart.
Similar restraints are also presented when attempts are made to reduce the overall thickness of a notebook computer keyboard. One possibility which has been investigated and attempted is to simply reduce the keystroke distance in the notebook computer keyboard compared to its desktop counterpart. Using this design technique, the overall thickness of the notebook computer in its closed storage and transport orientation may be correspondingly reduced. However, this thickness reduction in the overall notebook computer, achieved by reducing the keyboard keystroke distance, creates what many users consider to be an undesirable typing "feel" difference compared to the longer keystroke distance typically found in a larger desktop computer keyboard.
A different approach previously proposed to reduce the thickness of a notebook computer keyboard has been to provide the keyboard with the capability of being collapsed, in a direction parallel to that of its keystroke direction, when not in use. Potentially, at least, this approach would appear to have promise since a keystroke distance essentially identical to that in a larger desktop computer keyboard could be maintained when the keyboard was in its extended use orientation, while the thickness of the keyboard in its collapsed storage and transportation orientation is substantially reduced.
A disadvantage of this proposed approach has been the inability to incorporate in a collapsible keyboard structure a "pointing stick" type cursor control device. This device, as typically incorporated in a fixed height keyboard, is basically a stick-shaped member that is positioned generally centrally in the keyboard, in the space between a predetermined group of keys, and longitudinally extends parallel to the keystroke direction with the upper end of the pointing stick being at an elevation at or just slightly above the elevation of the top sides of the keys. User finger pressure exerted in a selected direction on the top end of the pointing stick is transmitted to an underlying pressure sensitive electronic circuit. The circuit responsively outputs an electrical signal which is used in a conventional manner to control the display screen position of a cursor.
Heretofore it has not been feasible to incorporate a pointing stick in a collapsible computer keyboard since when the keys are collapsed the upper end of the pointing stick remains at its previous height in which it is now a substantial distance above the elevation of the top sides of the collapsed keys. With the notebook computer lid closed, the outer side of the display screen cannot be brought into close proximity with the top sides of the collapsed keys since the upper end of the pointing stick is in the way. This characteristic of a conventional pointing stick, of course, would eliminate the advantage of the collapsing keyboard. Accordingly, it has heretofore been necessary to use some other type of cursor position control device, such as a mouse, trackball or touch pad, in conjunction with a collapsible keyboard.
As can be readily seen from the foregoing, it would be desirable to provide, in conjunction with a collapsible notebook computer keyboard structure which permits a useful thickness reduction in the closed computer without a corresponding reduction in the operative keystroke distance of the keyboard structure, a pointing stick device that eliminates the abovementioned disadvantage of a conventional pointing stick used with a collapsible keyboard. It is accordingly an object of the present invention to provide such a collapsible keyboard and associated pointing stick apparatus.